The present invention pertains to a swab analyzer for the immunochemical detection of substances with a housing, an eluent application zone and a reaction zone with a signal zone.
A process for detecting the contamination of a surface with an analyte by swabbing the analyte from the surface with a swabbing surface that is separate from a test strip, contacting the swabbing surface and the test strip, and subsequently applying an eluent with a subsequent immunological binding reaction, has become known from DE 44 39 429 C2. One drawback of this prior-art process and of the corresponding device is, on the one hand, that a separate swabbing surface must be present for the sampling and, on the other hand, that to contact the swabbing surface and the test strip by means of a special housing for receiving the test strip and the swabbing surface, the swabbing surface must be in contact with the test strip with a minimum pressure, but without preventing or hindering the capillary flow of liquid in the test strip.
Thus, the primary object of the present invention is to provide a swab analyzer of the type described in the introduction, which has a simple design, makes possible improved handling with good sensitivity of detection and has no separate swabbing surface for contacting with a test strip as according to the state of the art.
According to the invention, a swab analyzer is provided for the immunochemical detection of substances. The analyzer includes a housing, an eluent application zone and a reaction zone with signal zone. The housing has a local elevation with a central opening, from which a sampling and eluent application zone designed as a porous swabbing pen projects. The local elevation is provided with an at least partially circular collection groove for receiving excess eluent. A window is present in the housing at a spaced location from the local elevation for evaluating the reaction zone placed under it. The sampling and eluent application zone as well as the reaction zone with the signal zones are in capillary fluid connection with one another.
One essential advantage of the swab analyzer according to the present invention is the reliable, facilitated handling and the selective sensitivity of detection due to the selected porosity and the material of the combined sampling and eluent application zone designed as a swabbing pen. The combined sampling and eluent application zone (swabbing pen) is integrated with the analytical system in one housing.
The local elevation may be conical.
The collection grooves running around the local elevation may be concentric.
The porous surface of the swabbing pen projecting outward from the housing may be rounded. The pore size of the swabbing pen preferably ranges from 10 xcexcm to 100 xcexcm. The swabbing pen may consist of a sintered or foamed plastic, especially sintered polyethylene.
The housing can be opened and may consist of a plastic, especially polypropylene.
Using the present invention, substances located on surfaces can be collected and analyzed by manual swabbing with the sampling and eluent application zone designed as a porous swabbing pen. The dropwise application of a specific eluent to the sampling and eluent application zone elutes the analyte present in or on the collected substance into the reaction zone by capillary transport.
There is a need for analyzing substances located on surfaces in both forensic chemistry, environmental analysis and the medical diagnosis of secretions, such as sweat and saliva.
Proteins (allergens) adsorbed on very fine dust particles have been known to cause undesired allergic reactions in sensitized subjects. The pathogenic action of the allergens is concentration-dependent. Specific limit values have been specified, e.g., for mite and cat allergens in house dust. Checking these limit values of the concentrations within the framework of the probing of the exposure potential requires the collection of the very fine dust on a great variety of surfaces, such as mattresses, carpets, upholstered furniture, etc.
In addition, sampling from body fluids, such as sweat and saliva may be provided for establishing the genetic fingerprint. In addition, tests are performed, e.g., from immunological components (such as secretory antibodies) or pharmacological active ingredients in saliva and or sweat. It is common practice in these cases to take swab samples from the skin or from the pharyngeal cavity, which are usually evaluated in a separate analytical procedure.
Thus, the device according to the present invention is used for detection procedures in which the sampling by means of swabbing on surfaces is an integral or associated component of a subsequent analytical procedure with optically perceptible display for a measured concentration of a certain analyte.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.